From afe78ba0aae4f6cb2727adf25a014427ed730d11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adam=20M=C3=BAdry?= <mudry.ado@gmail.com>
Date: Sun, 7 Aug 2022 17:45:23 +0200
Subject: [PATCH] sdspi: Allow CS line to be set to GPIO_NUM_NC (-1)

Closes https://github.com/espressif/esp-idf/issues/7852
---
 components/driver/include/driver/sdspi_host.h |  1 +
 components/driver/sdspi_host.c                | 33 +++++++++++++------
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/components/driver/include/driver/sdspi_host.h b/components/driver/include/driver/sdspi_host.h
index 61f29811dd..63ad84aeab 100644
--- a/components/driver/include/driver/sdspi_host.h
+++ b/components/driver/include/driver/sdspi_host.h
@@ -63,6 +63,7 @@ typedef struct {
     gpio_num_t gpio_int;    ///< GPIO number of interrupt line (input) for SDIO card.
 } sdspi_device_config_t;
 
+#define SDSPI_SLOT_NO_CS    GPIO_NUM_NC ///< indicates that card select line is not used
 #define SDSPI_SLOT_NO_CD    GPIO_NUM_NC ///< indicates that card detect line is not used
 #define SDSPI_SLOT_NO_WP    GPIO_NUM_NC ///< indicates that write protect line is not used
 #define SDSPI_SLOT_NO_INT   GPIO_NUM_NC ///< indicates that interrupt line is not used
diff --git a/components/driver/sdspi_host.c b/components/driver/sdspi_host.c
index a09a63595d..1c7f69949d 100644
--- a/components/driver/sdspi_host.c
+++ b/components/driver/sdspi_host.c
@@ -43,7 +43,7 @@
 typedef struct {
     spi_host_device_t   host_id; //!< SPI host id.
     spi_device_handle_t spi_handle; //!< SPI device handle, used for transactions
-    uint8_t gpio_cs;            //!< CS GPIO
+    uint8_t gpio_cs;            //!< CS GPIO, or GPIO_UNUSED
     uint8_t gpio_cd;            //!< Card detect GPIO, or GPIO_UNUSED
     uint8_t gpio_wp;            //!< Write protect GPIO, or GPIO_UNUSED
     uint8_t gpio_int;            //!< Write protect GPIO, or GPIO_UNUSED
@@ -120,13 +120,17 @@ static slot_info_t* remove_slot_info(sdspi_dev_handle_t handle)
 /// Set CS high for given slot
 static void cs_high(slot_info_t *slot)
 {
-    gpio_set_level(slot->gpio_cs, 1);
+    if (slot->gpio_cs != GPIO_UNUSED) {
+        gpio_set_level(slot->gpio_cs, 1);
+    }
 }
 
 /// Set CS low for given slot
 static void cs_low(slot_info_t *slot)
 {
-    gpio_set_level(slot->gpio_cs, 0);
+    if (slot->gpio_cs != GPIO_UNUSED) {
+        gpio_set_level(slot->gpio_cs, 0);
+    }
 }
 
 /// Return true if WP pin is configured and is low
@@ -248,7 +252,9 @@ static esp_err_t deinit_slot(slot_info_t *slot)
         .mode = GPIO_MODE_INPUT,
         .intr_type = GPIO_INTR_DISABLE,
     };
-    gpio_config(&config);
+    if (pin_bit_mask != 0) {
+        gpio_config(&config);
+    }
 
     if (slot->semphr_int) {
         vSemaphoreDelete(slot->semphr_int);
@@ -332,13 +338,20 @@ esp_err_t sdspi_host_init_device(const sdspi_device_config_t* slot_config, sdspi
         .mode = GPIO_MODE_OUTPUT,
         .pin_bit_mask = 1ULL << slot_config->gpio_cs,
     };
-
-    ret = gpio_config(&io_conf);
-    if (ret != ESP_OK) {
-        ESP_LOGD(TAG, "gpio_config (CS) failed with rc=0x%x", ret);
-        goto cleanup;
+    if (slot_config->gpio_cs != SDSPI_SLOT_NO_CS) {
+        slot->gpio_cs = slot_config->gpio_cs;
+    } else {
+        slot->gpio_cs = GPIO_UNUSED;
+    }
+
+    if (slot->gpio_cs != GPIO_UNUSED) {
+        ret = gpio_config(&io_conf);
+        if (ret != ESP_OK) {
+            ESP_LOGD(TAG, "gpio_config (CS) failed with rc=0x%x", ret);
+            goto cleanup;
+        }
+        cs_high(slot);
     }
-    cs_high(slot);
 
     // Configure CD and WP pins
     io_conf = (gpio_config_t) {